Question

Tìm x biết \(|^1_2x+3|=\dfrac{2}{5}\)

Answer 1

\(\left|\dfrac{1}{2}x+3\right|=\dfrac{2}{5}\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x+3=\dfrac{2}{5}\\\dfrac{1}{2}x+3=-\dfrac{2}{5}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x=-\dfrac{13}{5}\\\dfrac{1}{2}x=-\dfrac{17}{5}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{26}{5}\\x=-\dfrac{34}{5}\end{matrix}\right.\\ \Rightarrow S=\left\{-\dfrac{26}{5};-\dfrac{34}{5}\right\}\)

Answer 2

`|1/2x+3|=2/5`
`+)1/2x+3=2/5`
`<=>1/2x=-13/5`
`<=>x=-26/5`
`+)1/2x+3=-2/5`
`<=>1/2x=-17/5`
`<=>x=-34/5`
Vậy `x=-26/5` hoặc `x=-34/5`

Answer 3

bạn bỏ trị đi rồi tính như thường nha.

mik chỉ bt tính 1 vế thôi

Answer 4

TH1:                                TH2:

1/2x+3=2/5                       1/2x+3=-2/5     

1/2x=2/5-3                         1/2x=-2/5-3

1/2x=-13/5                          1/2x=-17/5

x=-13/5:1/2                           x=-17/5:1/2

x=-26/5                                  x=-34/5

vậy.....

Answer 5

\(|^1_2x+3|=dfrac{2}{5}\)

Answer 6

\(\left|\dfrac{1}{2}x+3\right|=\dfrac{2}{5}\) 

\(\Rightarrow\dfrac{1}{2}x+3=\dfrac{2}{5}\) hoặc \(\dfrac{1}{2}x+3=\dfrac{-2}{5}\) 

               \(x=\dfrac{-26}{5}\) hoặc \(x=\dfrac{-34}{5}\)

Answer 7

`|1/2 x +3|=2/5`